bug#66416: 29.1; Crashes when visiting HELLO file with pgtk on Wayland

[Eli Zaretskii <eliz@gnu.org>]

[Pleased use Reply All to reply, so that the bug tracker is CC'ed.]

> From: Yuchen Guo <yguo@posteo.net>
> Date: Mon, 09 Oct 2023 18:18:51 +0000
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > Regardless of our attempts to understand the immediate reason(s) for
> > these crashes and try preventing them, your setup, viz.:
> > ...
> > is not a good idea, to say the least.
> 
> After setting up Emacs exactly the way you described, the original
> problem is fully resolved, it seems.  Again, this is my new config[1].

Regardless of this, we would still like to see a full human-readable
backtrace with your original setup, so that we could prevent those
crashes if that is feasible.

> I think it is advisable to include information on how to properly
> configure font fallback in the manual.  As someone who had just
> completed (eintr), it was indeed a frustrating experience trying to get
> the font fallback correctly configured.

Emacs is supposed to be properly configured regarding fonts out of the
box.  If the default configuration somehow didn't work for you, please
describe the problems, and we will see if the defaults need some
changes.

Setting the font sets manually is a tricky business which requires
some non-trivial understanding of scripts, fonts, text-shaping
requirements and expectations, etc., and is quite hard to explain in a
comprehensive way that will cover enough use cases.  Therefore, we try
to have the defaults that work for the users, such that manual
customizations are reserved for rare cases and for people who know
what they are doing.  We don't want to confuse users with too many
technical explanations and details about font setup.

> CJK users would appreciate such instructions due to Han Unification[2].

What are the issues with font setup that Han Unification causes to
Emacs users?